Composite optical elements including a first optical component and a second optical component coupled to the first optical component have already been known. The composite optical element may be manufactured by moving the first optical component and a molding die having a molding surface of a predetermined shape relatively close to each other to press-mold a softened resin placed between the first optical component and the molding surface into the second optical component coupled to the first optical component.
For example, according to the disclosure of Patent Literature 1, the molding die mounted on a nut of a ball screw is linearly moved close to the first optical component by driving the ball screw to rotate by a pulse motor so that a softened resin placed between the first optical component and the molding surface is press-molded into a predetermined shape, and then the molded resin is cured. In this way, the second optical component is coupled to the first optical component. More specifically, as the molding die is moved toward the first optical component, the softened resin is pressed and extended between the molding surface of the molding die and the first optical component. Then, the molding die is stopped when it comes to a predetermined forward position. In this way, molding of the resin is completed. The molding die is controlled to stop at the predetermined forward position as the pulse motor controls an angle of rotation of the ball screw. The softened resin is molded into a predetermined shape corresponding to the shape of space left between the molding surface at the forward position and the first optical component to become the second optical component. Then, the molded resin (second optical component) is cured to be coupled to the first optical component to manufacture the composite optical element.
Patent Literature 1: Publication of Japanese Patent Application No. 2001-249208